Apparatus for packaging nails and similar articles



Dec 13, 1966 K. w. MACDONALD ETAL 3,2%,081

APPARATUS FOR PACKAGING NAILS AND SIMILAR ARTICLES Filed April 14, 19648 Sheets-Sheet 1 /l/ l/l/ /I /l/ I/l/'l/ ./l/l/l//l/l ,/f/ /l S MNH/wwwww# Dec' 13, 1966 K. W. MACDONALD ETAL 3,291,081

APPARATUS Fon PACKAGING NAILs AND SIMILAR ARTICLES Filed April '14, 19648 Sheets-Sheet' 2 d, ,A A .ZZ ff A .My W ZWJW fla/m Y @i KM 2/d, @w AAAm A; W 5% Dec. 13, 1966 K. w. MACDONALD ETAL @,ZQLM

APPARATUS FOR PACKAGING NAILS AND SIMILAR ARTICLES Filed April 14, 19648 Sheets-Sheet 3 z @Md/ew @W4 5MM) 9L ,777@ W Dec. 13, 1966 K. w.MACDONALD ETAL 3,291,081

APPARATUS FOR- PACKAGING NAILS AND SIMILAR ARTICLES Filed April 14, 19648 Sheets-Sheet 4 Dec. 13, 1966 K. w. MACDONALD ETAL. 3,291,081

APPARATUS FOR PACKAGING NAILS AND SIMILAR ARTICLES Filed April 14, 19648 Sheetsheet 5 Dec. 13, 1966 K. w` MACDONALD ETAL 3,291,081

APPARATUS FOR PACKAGING NAILS AND SIMILAR ARTICLES Filed April 14, 19648 Sheets-Sheet 6 De@ 13, 1966 K. W. MACDONALD ETAL 3,291,081

APPARATUS FOR PACKAGING NAILS AND SIMILAR ARTICLES Filed April 14, 1964i @HA Wimimm .bldyllml-i a sheets-sheet '1 A Dec. 13, 1966 K. w.MACDONALD ETAL 3,291,03

APPARATUS FOR PACKAGING NAILS AND SIMILAR ARTICLES Filed April 14, 19648 Sheets-Sheet 8 @enfans nited States Patent O 3,291,081 APPARATUS FRPACKAGING NAILS AND SIMILAR ARTICLES Kenneth W. MacDonald, Bridgewater,Robert W. Nickelson, New Bedford, and Alan I. Maher, Bridgewater,

Mass., assignors to The Independent Nail Corporation,

a corporation of Delaware Filed Apr. 14, 1964, Ser. No. 359,584 16Claims, (Cl. 112-104) This invention relates to automatic high speedhandling and packaging of nails Vand similar articles, and moreparticularly is concerned with providing a method and apparatus forproducing a loaded clip of a type di rectly suitable for use in naildriving machines, the loaded clip comprising an elongated carrier striphaving a series of nails stitched thereto in a predetermined single le,side-by-side relation established by preformed grooves provided in suchstrip. The nails are oriented obliquely to the strip in the preferredloaded clip arrangement and to prevent endwise projection of the nails,the grooveless ends of the strip are extended beyond the endmost nails.

The principal object of the invention is to provide an automatic machineto deliver nails at timed intervals and properly oriented for locationin and individual securement in uniformly spaced side-by-side receivinggrooves provided in elongated carrier strips.

Another object of the invention is the provision in such a machine ofmeans for synchronizing delivery and deposit of nails individually ineach groove with stitching of each nail individually to retain it in itsgroove.

Still another object of the invention is the provision in such a machineof one or more of the following:

Means for automatically supplying strips in endwise succession; meansfor advancing each strip endwise in step-by-step fashion to registerfirst with a nail delivery point and then with a stitch point; meansresponsive to each strip for sensing the groove capacity and groovepositions thereof; me-ans for metering nails in quantities correspondingto the groove capacity of the strip and for delivering the meteredquantity of nails individually and in timed relation to fill each grooveof the strip in succession; positive mechanical registry mechanismengageable with each groove in the strip to register the positionthereof continuously with respect to the nail delivery point and thestitch point; and means for cutting off the stitching thread after eachstrip is loaded to enable discharge of the loaded clips individually.

A further object of the invention is the provision of a means and methodfor feeding and metering nails in closely spaced side-by-side relation,and delivering such nails individually in endwise orientation at regularintervals for deposit within receiving grooves located in sideby-sidespaced relation in an elongated carrier strip that is advancedstep-by-step at corresponding intervals.

High speed automatic packaging of nails in predetermined arrangement inpreformed receiving grooves requires high precision in the stripmovement and in the nail delivery; and synchronization of these actionsis important. Where the nails are to be secured to the strip by means ofindividually stitching each nail, the stitching cycle must be carefullysynchronized with both strip movement and nail delivery.

In accordance with this invention, the strip movement establishes eachgroove in registry first with the nail delivery point and then with thestitch point and this is conveniently provided by imparting movement tothe strip primarily by the stitching needle to advance the strip onegroove pitch during each stitch cycle. Accuracy of strip registry at thenail receiving point, however, is determined by mechanical registrydevices that engage directly in each of the successive grooves. Thisachieves a repeatable accuracy that may not be :realized by directcontrol from the stitching needle, as any error in its action mayaccumulate to serious proportions.

The nails to be inserted in the grooves are force fed at high speed tobe delivered individually and in time spaced relation at a single naildelivery point. The nail ilow is timed to start up at the beginning ofeach strip cycle by mechanical sense elements that respond to the firstgroove of the approaching strip, and nail ow is interrupted under thecontrol of these sense elements which also respond to the last groove ofthe departing strip.

In the preferred form illustrated in this disclosure, the carrier stripsyare moulded to present a series of side-byside spaced receivinggrooves, each of which is interrupted centrally to define a lengthwiseregion on the strip where a line of stitching is applied.

Other objects and advantages of this invention will be apparent duringthe course of the following description.

In the -accompanying drawings forming a part of this specification, andin which like numerals are employed to designate like parts throughoutthe same:

FIG. l is a fragmentary side elevational view illustrating a loaded clipof the type to be produced in accordance with this invention;

FIG. 2 is a generalized perspective view illustrating the overallarrangement of the principal components of the machine of thisinvention;

FIG. 3 is a front elevational view illustrating the overall arrangementof the principal components and the driving arrangement therefor;

FIG. 4 is a plan view of the machine;

FIGS. 4A and 4B are details of a thread cut-off unit and are taken onthe lines 4A-4A and iB-4B, respectively, of FIG. 4;

FIG. 5 is lan enlarged detailed elevational view of a nail counter andfeed unit and is taken approximately as indicated by the line S-S onFIGS. 3 and 4;

FIG. 6A is an enlarged detailed elevational view of the work station andillustrating various control mechanisms located thereat;

FIG. 6B is a plan view of the work station arrangement of FIG. 6A;

FIGS. 7A and 7B are fregmentary side elevational views of the workstation illustrating sequential positions of the elements during atypical stitch cycle;

FIGS. 8A and 8B are plan views corresponding respectively to FIGS. 7Aand 7B;

FIG. 9 is a diagram of a nail counting control circuit arrangement andincludes a sequence of views illustrating a typical operating cycle ofstrip sensing facilities that control this circuit;

FIGS. 10A and 10B are detailed sectional views taken on the lines10A-10A and 10B- 10B respectively as indicated in FIG. 5;

FIG. 11A is an enlarged fragmentary plan view illustrating the -movementof nails through the feed screw unit;

FIG. 11B is a fragmentary sectional view taken on the line 11B-11B ofFIG. 11A;

FIG. 11C is an end view partly in section taken as indicated on the line11C-11C of FIG. 11A; and

FIG. 12 is a timing chart for the machine.

Loaded clip Referring now to the drawings, and more particularly, toFIG. 1, there is illustrated a loaded clip C lof the type that is to bemass produced in accordance with the teachings of this invention. Thisloaded clip C is useful directly in nail driving machines and the likeand it also conveniently may serve as a storage and shipping package tofacilitate handling of nails during delivery, inventory, and sale. Theclip is comprised of an elongated molded carrier strip S, loaded with aset of nails N, arranged in essentially parallel single file,side-by-side relation in grooves G provided along an open side face ofthe strip. Each groove G is comprised of and defined by hollowed pocketsaligned in spaced relation to flank an elongated central portion of thestrip. The nails are retained on the strip by a continuous line ofstitching L provided in the elongated central portion so that each nailand the central strip region there adjacent is encircled by anindividual stitch.

Various types of nails other than that which is illustrated here may `bepackaged with the same type of carrier strip. The invention alsocontemplates packaging of other elongated fasteners such as screws,paper fasteners, and similar articles in similar types of carrierstrips, all in accordance with the techniques described hereinafter, Forconvenience, however, the term nail is used throughout the specificationand claims, but it shall be understood to embrace similar types ofarticles as mentioned so long as such articles may be handled in asimilar fashion.

The strips S are preferably molded from a fibrous material such as ismarketed under the trade name CEL-U- MOL and each strip may have a setof 50 nail receiving grooves G in regularly spaced side-by-side relationalong an intermediate length section thereof. The grooves extendgenerally crosswise of the strip direction and preferably are inclinedat an angle to normal on the order of 16.

In a typical strip construction, a groove and stitch pitch spacing of0.232" is employed between the fifty adjacent grooves. As there are 56stitch pitches in a strip, each end will extend beyond the midpoint ofeach endmost groove. Thus the leading end of the strip projects 31/2stitch pitches beyond the leading groove and the trailing end of thestrip projects 21/2 stitch pitches beyond the trailing groove. Therequirement is occasioned by the nailing machines in which the loadedclips are used and it is accommodated by providing special arrangementsfor metering and feeding of nails in synchronized relation for depositin the strip grooves.

General machine arrangement In FIG. 2 there is shown a generalarrangement for a preferred machine employed for feeding nailsindividually to and threadedly securing nails individually in theelongated carrier strips S to produce the final loaded clips C of FIG.l. Accordingly, as generally represented, the machine comprises a stripstorage and feed station 20 for feeding strips individually and insuccession to a strip travel path that has infeed means 21 forregulating strip approach travel, a work station 22 intermediatelytherealong, and delivery conveyor means 23 for regulating stripdischarge travel. The carrier strips S are moved through the workstation 22 in an accurately registered lstep-by-step action tomomentarily register each nail receiving groove of each strip first witha nail delivery point 24 (FIG. 6B) and then with a stitch point 25 (FIG.6B), with these points having a predetermined integer groove pitchspaced relation along the travel path. Preferably, these points 24 and25 are spaced apart a single groove pitch to facilitate securement ofeach nail immediately following deposit in its corresponding groove.

The nails `are delivered from a storage drum 26 to an inclined nailraceway 27 along which the nails move in side-by-side rearwardlyinclined shingled relationship. The nail raceway is centered upon a nailcounter and feed unit 28 through which the nails are metered atregularly spaced intervals into an air line 29 that defines a flowconduit leading to and defining the nail delivery point 24. The nailsmove individually and in endwise orientation through the air line 29 athigh speed under the control of a force feed such as may be provided bypneumatic pressure. t

A stitcher machine 30 constitutes the main structural component of thedisclosed arrangement and it is preferably of the so-called shoe-stitchtype in that it includes an awl 30A for puucturing holes in the stripmaterial to provide for subsequent entry of a needle 30N (see FIGS. 7Aand 7B). By way of example, the basic stitcher machine 30 may be of atype manufactured by the Puritan Manufacturing Co. under theirdesignation, Low-Post Single- Needle Sewing Machine. This machineproduces a chain stitch comprised of successive distinct loops, eachconfining a nail in a corresponding groove.

In general, the stitcher machine 30 has a movable yoke 31 underlying thework station 22 and reciprocally movable in the strip travel directionand a stationary head 32 overhanging the work station. The yoke 31 hasinternal mechanism for raising and lowering the needle 30N and this inconjunction with the yoke `movement generates a loop-shaped needletravel path. The yoke 31 also carries a cast-off 30C that is movableconjointly with the yoke to maintain proper relationship for removingeach thread loop as it is drawn down by the needle 30N.

The head 32 carries the awl 30A and a thread guide 30G which rotatesabout a vertical axis to wind one turn of thread about the needle 30Nduring each forward stroke thereof.

A thread cut off unit 33 is located at the exit side of the work station22 and operates once for each strip cycle to sever the thread at thetrailing end of each strip, after each such strip has been fully loadedand is partially engaged in the delivery conveyor 23. The belt speed atthe delivery conveyor 23 is somewhat greater than the travel speed of astrip through the stitching station to apply a pulling tension to thenext strip, assisting strip indexing action of the needle, therebyrelieving the needle 30N of excessive strain during the feed stroke. Thethread cut-off unit 33 severs the thread between strips after a striphas exited from the stitching station and the delivery conveyor 23carries away the loaded -strip at top belt speed for delivery tosuitable packaging facilities. Momentarily, the next strip is advancedby the action of the needle 30N and without the assistance of thedelivery conveyor until the lead end of the strip enters the belts ofconveyor 23.

In the preferred loaded clip package as illustrated in FIG. l, the nailfeed unit 28 is controlled to begin with the appearance of the firstgroove and to stop with the departure of the last groove. Nail countingand control mechanism is provided at the work station 22 to control anover-running clutch 104 located at the rear of the unit to establish anon-off drive from the continuously running sprocket 58 to theintermittently running feed unit 28 (FIG. 5). The nail counting andcontrol mechanism includes a pair of sense elements 34 and 35 (FIGS. 6A,6B and 9) lmovable upwardly through laterally spaced access slots 34Sand 35S provided to sense the arrival at the nail delivery point 24 ofthe lead groove in the strip and to sense the departure from the naildelivery point of the final groove of the strip. The sense elements 34and 35 are rotatable about a common pivot shaft 36 (FIGS. 6A and 6B)mounted in a stationary upright 37.

Strip register and indexing mechanism is provided along the stript-ravel path in advance of the nail delivery point and is operable toposition the strip during each step-bystep advance to assure registry ofeach strip groove with the nail delivery point 24 at the end of eachstep-by-step advance. For this purpose, a rst pawl 38 (FIGS. 6A and 6B)is pivotally mounted to a stationary bracket 38B carried on the machineand is resiliently biased by a torsion spring (not shown) normally toact downwardly to engage in a strip groove for maintaining the stripagainst accidental displacement, with the pawl 38 being free yieldableto ride up upon the strip face and permit step-by-step advance of thestrip as imparted by the stitching needle.

A second pawl 39 of identical form is pivotally mounted from the top -ofan oscillating indexing lever 40 which is driven in synchronism with thestitcher yoke 31 to generate a strip indexing movement that assists theneedle 30N in advancing the strip step-by-step. The indexing lever 40has its lower end pivoted to a stationary bracket 40B (FIG. 3) mountedon the base of the stitcher. An adjustable connecting rod 41 has itsopposite ends pivotally connected ,291,osi

to the stitcher feed yoke 31 and the lever 40 for imparting to the pawl39 a fore and aft movement corresponding to that imparted to the needle.The pawl 39 is biased by a torsion spring (not shown) to engage duringsuccessive cycles in successive grooves of the strip. This pawl 39 thusremains in and moves with a particular -groove during the advance strokeof the needle 30N but is free to rise during the return stroke of theneedle at which time the strip position is maintained by the first pawl33. The connecting rod 41 has a threaded rod end 41T engaged to theindexing lever 40 to facilitate precise adjustment of the pawi 39 atinteger groove pitch spacings from the nail delivery point. Accurategroove pitch movement is imparted to the pawl 39 by the indexing lever40 b-y initial adjustment of the rod end 41T which is secured along avertical slot 40S that is provided in the indexing lever.

While the needle of the stitcher effectively synchronizes step-by-stepadvance of the strip with the nail feed, any error in the stripadvancing stroke of the needle becomes cumulative. The pawl 3S isprovided t-o achieve registry after each strip cycle and the pawl 39assists the needle in advancing the strip one groove pitch.

S lifcher action The stitching action is best illustrated in thesequence of elevational views 7A and 7B and corresponding plan views 8Aand 8B. The elements performing the stitching operation include the awl30A disposed vertically above the work table 22T which supports thestrip during passage through t-he work station and acting during itsdownstroke in each stitch cycle to punch a hole in the strip which isstationary at this particular time; the hooked needle 30N located belowthe table and executing a vertical upstroike along the line of the awlto enter the punched hole as the awl is withdrawn, with the needle thenmoving forwardly along the strip path to advance the strip one groovepitch; the thread guide 30G located above the work table adjacent to theawl and rotatable about a vertical axis to swing in a generally forwarddirection and wind one turn or -loop of thread around the hook of theneedle during the forward strip indexing movement of the needle; and acast-off 30C located below the table adjacent to and moving insynchronism with the yoke 31 to remove from the needle the thread loopwhich the needle has drawn through the strip and through the thread loopformed by the preceding cycle, thus to form a series of interlockingloops on the underside of the carrier strip. This is commonly called achain stitch.

Synchronized drive For each strip of quantity of 50 nails are deliveredat automatically timed intervals in synchronism with the movement of thecarrier strip grooves past the nail delivery point 24. Accordingly, themechanism for driving the nail feed unit 28 must be synchronized withmechanism for adancing the carrier strip S, groove by groove, throughthe work station 22. The particular stitcher machine 30 described abovehas a needle movement that enables the needle 30N to impart astep-by-step advancing movement to the strip. The needle stroke in thedirection of the strip travel path is selected to be approximately onegroove pitch.

The basic synchronized drive arrangement for the machine is shown inFIGS. 3 Iand 4 and includes a variable speed drive motor M connectedthrough a belt 42B and pulley 2P to drive a countershaft 42 which isequipped adjacent its front end with a pulley 43 (see FIG. 3) and whichis equipped at its rear end Awith a pulley 44 (see FIG. 4).

The front pulley 43 drives a belt 43B that is engaged to an intermediatepllley 43P carried on a stub shaft 43S which drives a sprocket 45 andchain 45C that is trained about a larger drive sprocket i6 of thedelivery conveyor 23. The sprocket 46 is carried on a shaft 47 thatmounts a drive gear 48 which meshes with a gear 49 carried on a shaft5ft. The shafts 47 and 50 drive belts 47B 6 and 50B respectively, whichare trained about idler rollers 47R and SGR to complete the deliveryconveyor 23.

The pulley 44 (FIG. 4) at the rear of the countershaft 42 drives a belt52 which is engaged on a pulley 53 mounted on a main drive shaft 54 ofthe stitcher machine 30. The main shaft 54 of the stitcher machine isadditionally equipped with drive sprockets 55 and 56 (FIGS. 4 and 5).Drive sprocket 55 engages a chain 57 that is trained about a sprocket 58mounted at the lrear of the nail feed unit 28 to drive the nail feedunit at one-to-one ratio for enabling the feed unit 28, when activated,to Supply one nail for each stitch cycle. Manual control apparatuscomprising treadles 140 and 141 are provided to permit the operator toeffect a single stitch cycle as well as a continuous stitching run. Theltreadle 140 provides a single stitch and the treadle 141 is depressedto bring about a continuous stitching action of the machine. Thetreadles are, of course, connected to the stitch drive in any suitablefashion to permit the desired degree of sensitivity and control.

Sprocket 56 (FIG. 4) is engaged to chain 59 to drive a sprocket 60 onthe infeed shaft 61 of a speed reducer unit 62. The speed reducer unit62 has an output shaft 63 equipped with a sprocket 64 engaged to a chain65 that drives a sprocket 66 mounted on a cam shaft 67, which extendslengthwise through the machine to control the time of actuation ofvarious equipment located along the strip travel path.

The cam shaft 67 is driven through one revolution every 56 stitch cyclesas required by the fact that the strip length is 56 groove pitches.Therefore, there yare 56 stitch cycles per strip cycle. The cam shaft 67has a mitre gear 68 driving =a mitre gear 69 to rotate a drive shaft 7dat the strip storage and feed station 20. The shaft 7i) is also equippedwith a sprocket 71 engaged to a chain 72 to drive a sprocket 73 carriedon a drive shaft 74 that operates the infeed means Z1 at the entry tothe strip travel path.

The strip storage and feed station Ztl has upstanding end walls 20Wdefining a storage magazine for a stack of carrier strips S. Thelowermost carrier strip S stored at station 20 is fed from the bottom ofthe stack under the control of a push-type feeder element 75 that isreciprocable in the fore and aft direction of the strip travel path. Themechanism for driving the feeder element 75 includes an eccentric link76 pivoted to a disc cam '77 that is drivingly mounted on shaft 70. Theeccentric link 76 is drivingly connected to a rocking link 78 to operatea connection link 79 that drives the feeder element 75.

The infeed means 21 includes a pair of superposed feed roller wheels 80and 81. Lower roller wheel 80 is mounted in a friction unit (not shown)fastened to shaft 74. Upper roller wheel 81 is moutned in a frictionunit (not shown) fastened to shaft 83. The shafts 74 and 83 are drivenfrom mating gears 32 by means of Vsprocket 73 which is carried on shaft74.

The roller wheels 80 and 81 normally operate to advance eac-h strip morerapidly than the advance of the preceding strip through the work station22 as controlled by the needle 30N. This enables the strips to be fedcontinuously so as to avoid gaps between strips. The approaching stripis advanced solely by the action of the roller wheels 80 and 81 untilthe lead groove in the strip can be picked up and -controlled by theindexing pawl 39. At this point the feed roller wheels will begin toslip and leave further strip -advance to the pawl 39 for effectingaccurate registry of each strip as it approaches the work station.

The cam 85 is configured to completely disengage the rollers Si) and 81after the pawl 39 takes control of strip advance. This is accomplishedby the cam 86 causing the frame 85 to pivot in a fashion to elevate theupper roller wheel 81 once during each strip cycle for a time intervalsufficient to permit the final two inches of the strip to clear theroller wheels as the strip is advanced up to and into the work station22.

(A) Nail hold down device During the indexing of the carrier strip fromthe nail delivery point 24, wherein a nail is injected into the groovemomentarily `aligned therewith, to the stitch point 25, it is necessaryto retain the injected nail in its groove to guard against thepossibility of the nail popping out. The work table 22T at the Workstation mounts a clamp 90 that anchors the delivery end of the feed tube29 at the prescribed orientation for alignment with each successivegroove that is to be progressed therethrough. Thus, the tube 29 lisaligned in a particular direction at a particular location to define thenail delivery point 24.

The details of the structure for retaining a nail against popping outare best shown in FIGS. 7A, 7B, 8A and 8B. At its outboard end, the worktable 22T is provided with a bracket 91 that extends crosswise above thetravel path of the strips S to mount a retaining shoe 92. An upstandingbifurcated post 921 is mounted on the bracket and carries -a pivot axle92A that mounts the shoe 92 for swinging movement about a horizontalaxis. A compression spring 92S reacts between the bracket 91 and theshoe 92 normally to urge the shoe into nail contacting engagement. Thehead 32 of the stitcher machine is provided with a vertically reciprocalrod 93 that carries a presser foot 94 at its lower end. The under face94F of the presser foot is provided with three grooves, 95, 96 and 97(See FIG. 8A), one 95 for alignment with the delivery tube 29 to servein conjunction with the corresponding strip groove as a guide conduitduring nail entry; a second 96 to hold the previously injected nail inplace during looping of a stitch thereabout; and a third 97 engageableupon the previously stitched nail to align and position the strip aftereach index movement thereof.

The operating sequence of these elements may now be described. Thepresser foot 94 moves downwardly and its actuating rod 93 includes alaterally projecting finger 93F that overhangs the retaining shoe 92 tomove downwardly against the shoe and cause the shoe to -be lifted at thetime that the presser foot goes down upon the nail ystrip (see FIG. 7A).At this position of the parts, a nail is supplied through the tube 29-and guided into place by the rightmost groove 95 of the presser foot 94which is in mating coaction with the corresponding strip groove.Thereafter the presser foot rises to permit the retaining shoe 92 tocome down and engage the delivered nail to prevent its popping out asthe needle 30N moves first upwardly and then to the left to advance thestrip to bring the deposited nail to the stitch point. The presser footthen comes down again and the cycle is repeated. A presser foot liftpedal 142 is provided, and is connected to the presser foot mechanism insuch a manner that, upon depression of the treadle, the presser foot iscaused to lift a sufficient amount to permit removal of, or insertion ofa strip or a nail, or both.

(B) Nail counting control As mentioned previously, the sense elements 34and 35 shown in FIGS. 6A, 6B, and 9 are provided to control turn-on andturn-oli" of the nail feed unit 28. The sense elements 34 and 35 are inalignment crosswise of the strip travel path and are arranged normallyto ride upwardly against the strip S to engage and be deflecteddownwardly in the presence of the strip groove portions. Sense element34 is associated with a control switch 100 and sense element 35 isassociated with a control switch 101. Eac-h of the control switches areopen when the sense elements are uppermost and are closed when the senseelements move downwardly in response to the presence of the stripgrooves.

The sense elements 34 and 35 are aligned crosswise of the strip travelpath and are spaced apart so that the Q inclination of the strip groovescauses sense element 34 to be operated one groove pitch sooner thansense element 35 upon the arrival of the lead groove of the strip S andso that sense element 34 returns to normal one groove pitch prior tosense element 35 upon departure of the final strip groove.

T-he control switches are connected in series in an energizing circuitfor a solenoid 102 as shown in FIG. 9. The circuit is open unless bothsense elements 34 and 35 are actuated by engagement with a strip grooveregion. Thus, as the lead strip groove approaches the sense elements asindicated in FIG. 9, both switches and 101 are open prior to the arrivalof the first groove. As indicated in sequence A of FIG. 9, the leadgroove actuates sense element 34 to close its control switch, and atthis time, sense element 35 is not yet actuated. As shown in sequence Bof FIG. 9, the second strip groove holds Sense element 34 actuated tomaintain its control switch 100 closed, this being insured by providingthe contact face 34F of a length of one groove pitch. At this time thelead strip groove has now actuated sense element 35 which has a contactface 35F also of one groove pitch in length. Thus, in sequence B, bothcontrol switches are closed and the solenoid is energized and remainsenergized while the intermediate grooves of the strip move by. Finally,as shown in sequence C the final strip groove moves clear of senseelement 34, first allowing the control switch 100 to open andde-energize the solenoid.

This nail counting control counts accurately the number of grooves ineach strip and functions as a safety device in that nails will start tofeed only when a strip is present. If a single sense element were used,one extra nail would be fed `and this would foul up the entireoperation.

The solenoid 102 has `an armature 102A reciprocably movable to controlthe positioning of a link 103 that regulates the condition of engagementof an overrunning clutch 104 which drives the nail feed unit 28. Theoverrunning clutch 104 (FIG. 5) includes a driving element 105 connectedto be operated by the sprocket 58, and a driven element 106 which isconnected to drive an input shaft 107 to the nail feed unit 28, Sincethe sprocket 58 normally operates continuously, the clutch members 105and 106 normally rotate continuously to transmit driving torque to thisinput shaft 107.

The driven clutch element carries with it an abutment stop 106A (seeFIGS. 5 and 9), which is to be engaged by the link 103 under the controlof the solenoid 102. As shown in FIG. 9, the link 103 is mounted topivot about ian axis 103A and is biased upward by tension spring 103Tnormally to hold the link 103 in engagement with the abutment stop 106Aon the driven member 106 of the clutch, so that driving contact of theinternal clutch rollers (not shown) is relieved and rotation of theshaft 107 is stopped, permitting the driving clutch element 105 and itssprocket 58 to free-wheel.

When a nail receiving groove is sensed through the elements 34 and 35 toenergize the solenoid 102, the link 103 is swung free and permits thedriven element of the clutch 106 to rotate and drive the nail feed inputshaft 107 continuously until such time as the solenoid 102 isde-energized to allow the spring 103T to pivot the link 103 intoblocking engagement with the abutment stop 106A. To preventobjectionable rebound action during this stop sequence, the input shaft107 is equipped with an outboard cam 108 as shown in FIGS. 5 and 9. Ashock lever 109 is spring biased towards the position illustrated inFIG. 9 to engage a shoulder on the cam 108 and block rebound at the timethat the driven clutch element 106 is stopped by the solenoid controlledlink 103.

(C) Nail metering and feed unit The feed unit 28 is shown generally inFIGS. 4 and 5 and includes an upper pair of twin screws 110 and 111 of3,291,osi

opposite leads (FIG. 10A) and a lower pair of twin screws 112 and 113 ofopposite leads, all rotating in the directions indicated in FIG. 10A. InFIGS. 2, 3, 5, 11A and 11B, the nail raceway 27 is shown leading intothe rear of the feed screw assembly. Each of the feed screws is mountedon a corresponding shaft 1105, 111S, 112S and 1138, the rearmost ends ofwhich are equipped with intermeshing spur gears 110G, 111G, 112G, and113G, respectively, operating at a 1 to 1 ratio. The shaft 112s for thelower spur gear 112G is aligned axially with the input drive shaft 107which is engaged in the spur gear 112G for driving the entire nailmetering and feed unit. Power is transmitted from gear 112G to the othergears to rotate all of the feed screws in synchronism.

The nail receiving ends of the feed screws are shaped and tapered topositively pick up one nail from the raceway 27 for each revolution ofthe shaft 107. The nails are thus conveyed in single file side-by-sidepositively spaced relation through the screws to enter a transfer block115 that is provided with a discharge chamber in the form of a bore 116that receives the nail in snug sliding relation for movement endwiseinto and through the delivery tube 29 which is connected into the lowerend of the block 115. The entry face 115F of the transfer block 115 hasa slot to enable each nail to move laterally into the bore 116.

For high speed nail handling applications, for example, 500 per minute,it is required to force feed the nails from the discharge chamber 116through the delivery tube 29. For this purpose, an air supply line 117is connected to the block 115 at the top of the discharge chamber and iscontrolled by an air valve 118 to apply air at a pressure on the orderof 80 p.s.i. for forcibly driving each nail through the delivery tube29. Operation of the air valve is synchronized by means of a cam 119that rotates on the end of the feed screw shaft 1128 as shown in FIG.11A to actuate a follower roller 120 associated with the valve 118. Thiscam actuates the operating roller 120 to trigger the air supply once foreach stitch cycle at a time phase following delivery of a nail into thedischarge chamber 116.

For most effective utilization of the air, a snug tit with the nail headis provided and it is important to seal the entry slot through the face115F of the transfer block 115 during application of air under pressure.For this purpose, the transfer block 115 mounts a slidable block 121that carries a plate-like gate 122 or shutter to block the entrance slotintermittently. Normally, the slide block 121 is held at a slot closingposition by means of a compression spring 123 as illustrated in FIG.11C. A roller 124 is mounted outboard of the slide block and isengageable by a cam 125 carried on the feed screw shaft 112S to controlclosure and opening of the gate 122.

In general, the sequence for each stitch cycle or for each nail feedcycle is to close the gate 122 immediately after delivery of a nail intothe discharge chamber, then to open the air valve 118 for apredetermined part of the cycle and then to close the valve 118 and openthe gate 122 for the remainder of the revolution. This is illustrated atthe bottom of the timing chart of FIG. 12.

(D) Thread cut-Ot unit The thread cut-off unit is illustrated at 33 inFIGS. 3, 4, 6A, and 6B, and it is operated in synchronized relation fromthe camshaft 67 the left hand end of which, as pictured in FIGS. 4 and4A, is equipped with a cam 126 that controls the time of activation ofarms 127 and 12S that are equipped with knife-edge elements 127K and128K respectively to sever the thread at a location between successivecarrier strips. The surface on cam 126 is configured to maintain thecutting arms open for 55/56 of a revolution.

On the 56th increment, the cam 126 frees the lever arm 130 carried atone end of a shaft 131 which is journaled in a frame-mounted bearingstructure 132. The other end of shaft 131 carries a knife element 127and also drives a 10 spur gear 133 which meshes with a cooperating spurgear 134 carried on a stub shaft 135 that pivots knife-element 128 insynchronism with element 127.

Internal springs (not shown) act to swing the knife elements togetherwhen the cam 126 frees the lever arm and this occurs at a time when thestrip is not moving, so that the thread may easily be severed to freethe completed strip for higher speed travel through the deliveryconveyor 23.

Thus, while preferred constructional features of the invention areembodied in the structure illustrated herein, it is to be understoodthat changes and variations may be made by those skilled in the artwithout departing from the spirit and scope of the appending claims.

What is claimed is:

1. Apparatus for assembling loaded clips each comprised of an elongatedcarrier strip having a given number of successive generally crosswisedirected receiving grooves disposed in regularly spaced side-by-siderelation therealong and a separate nail secured in each groove bylengthwise stitching that includes a distinct loop encircling a separatestrip portion adjacent each groove. said apparatus compris-ing means toadvance the strip in single groove pitch steps along a travel path thatincludes a work station having thereat a nail delivery point and astitch point located in successive integer groove pitch spaced relationalong the strip travel path, a stitcher at said work station andrepeatedly operable through a stitch cycle in synchronism with stripmovement steps to form successive stitch loops in encircling relation tostrip material at the stitch point, and nail counting and feed meansoperable in synchronism with said stitcher to supply one nail for eachstitch cycle to discharge in predetermined orientation into theparticular groove located at said nail delivery point, and saidapparatus including means operable once during each stitch cycle foradvancing said strip endwise in single groove pitch steps through saidwork station to establish each of successive grooves therein in registrywith the nail delivery point at the time of nail discharge therefrom andin registry with the stitch point at the time of stitch loop forming.

2. The apparatus of claim 1 and including presser foot means at saidwork station and cyclically movable in synchronism with the stripmovement steps to occupy a clearance position relative to the stripportion at said work station when the strip is in motion and to occupy anail holding position relative to the strip portion at said work stationwhen the strip is stationary.

3. The apparatus of claim 2 and including a nail contacting retainermeans at said work station and cyclically movable in synchronism withsaid presser foot means to occupy a clearance position relative to thestrip grooves at the nail delivery point and the stitch point when thestrip is stationary and to occupy a nail contacting position relative tonails in the strip grooves that are departing from the said points whenthe strip is in motion.

4. The apparatus of claim 1 and including a nail contacting retainermeans at said work station and cyclically movable in synchronism withthe strip movement steps to occupy a clearance position relative to thestrip grooves at the nail delivery point and the sitch point when thestrip is stationary and to occupy a nail contacting position relative tonails in the strip grooves that are departing from said points when thestrip is in motion.

5. The apparatus of claim 1 wherein the nail counting and feed means hasits nail delivery point alongside the strip travel path and oriented ina direction for endwise aligned registry with each strip groove andwherein the nail counting and feed means includes means to feed nailsindividually at high speed and in endwise orientation along a nailtravel path leading to the nail delivery point to enable endwise entryof each nail into its corresponding recelvmg groove.

6. Apparatus in accordance with claim 1 wherein the strip travel pathextends generally horizontally and each strip moving therealong has anupper exposed face provided with said receiving grooves and said nailcounting and feed means discharges each nail individually in a directionfor endwise aligned registry with its corresponding groove.

7. Apparatus for assembling loa-ded clips each comprised of an elongatedcarrier strip having a given number of succesive generally crosswisedirected receiving grooves disposed in regularly spaced side-by-siderelation therealong a separate nail secured in each groove by lengthwisestitching that includes a distinct loop encircling a separate stripportion adjacent each groove, said apparatus comprising means to advancethe strip in single groove pitch steps along a travel path that includesa work station having thereat a nail delivery point and a stitch pointlocated in succesive integer groove pitch spaced relation along thestrip travel path, a stitcher at said work station and repeatedlyoperable through a stitch cycle in synchronism with strip movement stepsto form successive stitch loops in encircling relation to strip materialat the stitch point, nail feed means operable in synchronism with saidstitcher to supply one nail for each stitch cycle to discharge inpredetermined orientation to the particular groove located at said naildelivery point, and count control means sensing t-he passage of eachstrip through said work station and actuating the nail feed means formetering said number of nails for sequential deposit individually insuccessive grooves of said strip, and said apparatus including meansoperable once during each stitch cycle for advancing said strip endwisein single groove pitch steps through said work station to establish eachof successive grooves therein in registry with the nail delivery pointat the time of nail discharge therefrom and in registry with the stitchpoint at the time of stitch loop forming.

8. Apparatus for assembling loaded clips each comprised of an elongatedcarrier strip having a number of successive generally crosswise directedreceiving grooves disposed in regularly spaced side-by-side relationalong an intermediate section of such strip and a separate nailindividually secured in each groove by lengthwise stitching thatincludes a distinct loop encircling a separate strip portion adjacenteach groove, said apparatus comprising means providing a strip travelpath and including a work station providing a nail delivery point and astitch point located in successive integer groove 'pitch spaced relationalong the strip travel path, a stitcher at said work station andrepeatedly operable through a stitch cycle to form successive stitchloops in encircling relation to strip material at the stitch point, saidstitcher including a stitch loop forming needle cy-clically movablethrough the plane of a strip, then forwardly along the strip travel pathto advance the strip one groove pitch, then oppositely through the planeof the strip and then rearwardly along the strip travel path, and nailcounting and feed means operable in synchronism with said stitcher tosupply one nail for each stitch cycle to discharge such nail endwisethrough the nail delivery point along a direction of endwise alignedregistery with a corresponding receiving groove during a time periodfollowing strip advancing movement of said needle.

9. Apparatus for assembling loaded clips each comprised of an elongatedcarrier strip having a number of successive generally crosswise directedreceiving grooves disposed in regularly spaced side-by-side relationalong an intermediate section of such strip and a separate nailindividually secured in each groove by lengthwise stitching thatincludes a distinct loop encircling a separate strip portion adjacenteach groove, said apparatus comprising means providing a strip travelpath and including a work station having thereat a nail delivery pointand a stitch point located in successive integer gro-ove pitch spacedrelation along the strip travel path, a stitcher at said work stationand repeatedly operable through a stitch cycle to form successive stitchloops in encircling relation to strip material at the stitch point, saidstitcher including a stitch loop forming needle cyclically movablethrough the plane of a strip, then forwardly along the strip travel pathto advance the strip one groove pitch, then oppositely through the planeof the strip and then rearwardly along the strip travel path, ,anelongated air chamber having a lateral entrance slot and a travelpassage capable of accommodating endwise nail travel exiting from oneend of said chamber and leading to said nail delivery point to dischargeeach nail endwise along a direction of endwise aligned registry with acorresponding receiving groove, positive motion feed means operating intimed relation with said stitcher for feeding nails in distinctly spacedside-by-side relation to supply nails into said chamber through saidslot individually at discrete intervals, and valve means operating intimed relation with said positive motion feed means to inject amomentary high pressure blast at the other end of said chamber aftereach nail is supplied thereto and eject each nail endwise from saidchamber to travel through said passage and exit from said nail deliverypoint when an empty strip groove is in registry therewith.

10. Apparatus for assembling loaded clips each comprised of an elongatedcarrier strip having a given number of successive generally crosswisedirected receiving grooves disposed in regularly spaced side-by-siderelation along an intermediate length section thereof and acorresponding number of nails individually secured in each groove bylengthwise stitching that includes a distinct loop encircling a separatestrip portion adjacent each groove, said apparatus comprising meansproviding a strip travel path and including a work station providing anail delivery point and a stitch point located in successive integergroove pitch spaced relation along the strip travel path, a stitcher atsaid work station and repeatedly operable through a stitch cycle to formsuccessive stitch loops in encircling relation to strip material at thestitch point, means for metering said number of nails for each strip andincluding positive motion feed means operating in timed relation withsaid stitcher to supply one nail for each stitch cycle to discharge inpredetermined orientation at said nail delivery point, a circuitconnected to control the time of operation of said metering means andincluding a first sense element responsive to leading portions of eachstrip groove and a second sense element responsive to trailing portionsof each groove and spaced from groovewise alignment with the lirst senseelement a single groove pitch distance, and means responsive only when`both sense elements are responding to actuate said circuit, and saidapparatus including means operable once during each stitch cycle foradvancing said strip endwise in single groove pitch steps through saidwork station to establish each of successive grooves therein in registrywith the nail delivery point at the time of nail discharge therefrom andin registry with the stitch point at the time of stitch loop forming.

11, Apparatus for assembling loaded clips each cornprised of anelongated carrier strip having a given number of successive generallycrosswise directed receiving grooves disposed in regularly spacedside-by-side relation along an intermediate length section thereof and acorresponding number of nails individually secured in each groove bylengthwise stitching that includes a distinct loop encircling a separatestrip portion adjacent each groove, said apparatus comprising meansproviding a strip travel path and including a work station providing anail delivery point and a stitch point located in successive integergroove pitch spaced relation along the strip travel path, a stitcher atsaid work station and repeatedly operable through a stitch cycle to formsucessive stitch loops in encircling relation to strip material at thestitch point, an elongated air chamber having a lateral entrance slotand a travel passage capable of accommodating endwise nail travelexiting from one end of said chamber and leading to said nail deliverypoint to discharge each nail endwise along a direction of endwisealigned registry with a corresponding receiving groove, means formetering said number of nails for each strip and including positivemotion feed means operating in timed relation with said stitcher tosupply one nail for each stitch cycle to discharge in predeterminedorientation at said nail delivery point, a circuit connected to controlthe time of operation of said metering means and including a first senseelement responsive to leading portions of each strip groove and a secondsense element responsive to trailing portions of each groove and spacedfrom groovewise alignment with the rst sense element a single groovepitch distance, and means responsive only when both sense elements areresponding to actuate said circuit, and valve means operating in timedrelation with said positive motion feed means to inject a momentary highpressure blast at the other end of said chamber after each nail issupplied thereto and eject each nail endwise from said chamber to travelthrough said passage and exit from said nail delivery point, and saidapparatus including means operable once during each stitch cycle foradvancing said strip endwise in single groove pitch steps through saidwork station to establish each of successive grooves therein in registrywith the nail delivery point at the time of nail discharge therefrom andin registry with the stitch point at the time of stitch loop forming.

12. Apparatus for assembling loaded clips each cornprised of anelongated carrier strip having a given number of successive generallycrossw'ise directed receiving grooves disposed vin regularly spacedside-by-side relation therealong and a corresponding number of nailsindividually secured in each groove along an intermediate length sectionof the strip by lengthwise stitching that includes a distinct loopencircling a separate strip portion adjacent each groove, said apparatuscomprising means providing a strip travel path and including a workstation providing a nail delivery point and a stitch point located insuccessive integer groove pitch spaced relation along the strip travelpath, means to advance the strip in single groove pitch steps toregister each receiving groove thereof successively with each said pointand including a stitcher at said work station and repeatedly operablethrough a stitch cycle to form successive stitch loops in encirclingrelation to strip material with said stitcher to supply one nail foreach stitch cycle to discharge in predetermined orientation into theparticular groove located at said nail delivery point, and -countcontrol means sensing the passage of each strip through said workstation and actuating the nail feed means for metering said number ofnails for sequential deposit individually in successive grooves of saidstrip, and said apparatus including means operable once during eachstitch cycle for advancing said strip endwise in single groove pitchsteps through said work station to establish each of successive groovestherein in registry with the nail delivery point at the time of naildischarge therefrom and in registry with the stitch point at the time ofstitch loop forming.

13. Apparatus for assembling loaded clips each comprised of an elongatedcarrier strip having a given number of successive generally crosswisedirected receiving grooves disposed in regularly spaced side-by-siderelation therealong and a separate nail secured in each groove bylengthwise stitching that includes a distinct loop encircling a separatestrip portion adjacent each groove, said apparatus comprising meansproviding a strip travel path and including a work station providing anail delivery point and a stitch point located in successive integergroove pitch spaced relation along the strip travel path, strip storageand supply means operable cyclically to supply strips successively tosaid strip travel path, means to advance each strip through said workstation in single groove pitch steps to register each receiving groovethereof successively with each said point and including a stitcher atsaid work station and repeatedly operable through a stitch cycle to formsuccessive stitch loops in encircling relation to strip material at thestitch point, nail feed means operable in synchronism with said stitcherto supply one nail for each stitch cycle to discharge in predeterminedorientation into the particular groove located at said nail deliverypoint, and count control means sensing the passage of each strip throughsaid work station and actuating the nail feed means for metering saidnumber of nails for sequential deposit individually in successivegrooves of said strip, and said apparatus including means operable onceduring each stitch cycle for advancing said strip endwise in singlegroove pitch steps through said work station to establish each ofsuccessive grooves therein in registry with the nail delivery point atthe time of nail discharge therefrom and in registry with the stitchpoint at the time of stitch loop forming.

14. Apparatus of claim 13 and including thread cutoi means followingsaid work station and operable in synchronism with said strip storageand supply means to severe the stitching at the trailing end of eachstrip after such strip clears the work station.

15. The apparatus of claim 13 and including a nail contacting retainermeans at said work station and cyclically movable in synchronism withsaid presser foot means to occupy a clearance position relative to thestrip grooves at the nail delivery point and the stitch point when thestrip is stationary and to occupy a nail contacting position relative tonails in the strip grooves that are departing from the said points whenthe strip is in motion.

16. The apparatus of claim 15 and including a rail contacting retainermeans at said work station and cyclically movable in synchronism withthe strip movement steps to occupy a clearance position relative to thestrip grooves at the nail delivery point and the stitch point when thestrip is stationary and to occupy a nail contacting position relative tonails in the strip grooves that are departing from said points when thestrip is in motion.

References Cited by the Examiner UNITED STATES PATENTS 9/1920 Kollmar112-104 1/ 1965 MacDonald et al 53--35

1. APPARATUS FOR ASSEMBLING LOADED CLIPS EACH COMPRISED OF AN ELONGATEDCARRIER STRIP HAVING A GIVEN NUMBER OF SUCCESSIVE GENERALLY CROSSWISEDIRECTED RECEIVING GROOVES DISPOSED IN REGULARLY SPACED SIDE-BY-SIDERELATION THEREALONG AND A SEPARATE NAIL SECURED IN EACH GROOVE BYLENGTHWISE STITCHING THAT INCLUDES A DISTINCT LOOP ENCIRCLING A SEPARATESTRIP PORTION ADJACENT EACH GROOVE, SAID APPARATUS COMPRISING MEANS TOADVANCE THE STRIP IN SINGLE GROOVE PITCH STEPS ALONG A TRAVEL PATH THATINCLUDES A WORK STATION HAVING THEREAT A NAIL DELIVERY POINT AND ASTITCH POINT LOCATED IN SUCCESSIVE INTEGER GROOVE PITCH SPACED RELATIONALONG THE STRIP TRAVEL PATH, A STICHER AT SAID WORK STATION ANDREPEATEDLY OPERABLE THROUGH A STITCH CYCLE IN SYNCHRONISM WITH STRIPMOVEMENT STEPS TO FORM SUCCESSIVE STITCH LOOP IN ENCIRCLING RELATION TOSTRIP MATERIAL AT THE STITCH POINT, AND NAIL COUNTING AND FEED MEANSOPERABLE IN SYNCHRONISM WITH SAID STITCHER TO SUPPLY ONE NAIL FOR EACHSTITCH CYCLE TO DISCHARGE IN PREDETERMINED ORIENTATION INTO THEPARTICULAR GROOVE LOCATED AT SAID NAIL DELIVERY POINT, AND SAIDAPPARATUS INCLUDING MEANS OPERABLE ONCE DURING EACH STITCH CYCLE FORADVANCING SAID STIRP ENDWISE IN SINGLE GROOVE PITCH STEPS THROUGH SAIDWORK STATION TO ESTABLISH EACH OF SUCCESSIVE GROOVES THEREIN IN REGISTRYWITH THE NAIL DELIVERY POINT AT THE TIME OF NAIL DISCHARGE THEREFROM ANDIN REGISTRY WITH THE STITCH POINT AT THE TIME OF STITCH LOOP FORMING.